Telephone system



J. WICKS TELEPHONE SYSTEM April 8, 1930.

Original Filed Sept. 26, 1925 Ski; v m5 E Patented Apr. 8, 1930 UNETED STATES PATENT oFFicE JOHN WICKS, or OAK PARK, ILLINOIS, ASSIGNOR, BY MESNE ASSIGNMENTS, r AVUTO-I MATIC ELECTRIC INC., on CHICAGO, ILLINOIS, A CORPORATION or DELAWARE TELEPHONE SYSTEM Application filed September 26, 1925, Serial No. 58,680. Renewed January 27, 1930.

The present invention relates to telephone systems in general, but it is concerned more particularly with telephone systems in which the switches in one ofiice are operated according to a given system of control, while the switches in an adjacent ofiice are operated according to another system of control.

One object of the invention is the production of a novel repeater circuit for use in incoming calls in one office to translate the control arising in the other ofiice so that the local switches may be correctly operated.

Another object is the production of Suitable circuit arrangements in the same office whereby the control of the distant switches may be eifected without the use of a special repeater in the distant office.

Still another object is the production of suitable circuit arrangements whereby the calling device may be connected by means of a special cord circuit directly to the trunk line to control the distant switches independent of any repeating operation.

Referring now to the accompanying drawings comprising a single sheet, Fig. 1 shows the two-way toll line TL together with certain associated equipment on one end thereof, and Fig. 2 shows the special cord circuit which is used to connect the calling device to the toll lines, there being separate cord circuits (not shown) for making talking connections to and from the toll line.

Before the drawings are described further, the situation which they are especially adapted to meet will be explained a little more in detail. It is assumed that there are two exchanges located sufficiently far from each other that the connections from one to the other are made through the switchboard of the toll operator.

It is assumed as before intimated that the switches in the two diiferent exchanges are operated according to different systems of control. More specifically, the switches in the oflice in which the equipment shown in the drawings is located are operated according to the well known two-wire system of control, while the switches in the other office are operated according to a modified system of control; According to this modified system, the setting of the switches is accomplished over one conductor and a ground return. The other conductor is used to switch the circuits at the exchange into condition to receive the switch operating impulses only while the calling device is off-normal, and is used for supervisory purposes.

It is assumed that it has been found to be most economical to make all the changes in the straight two-wire o'tfice permitting the circuits in the other office to remain unchanged.

It usually happens that when an automatic exchange is installed it replaces a manual exchange. The manualtoll board however is usually retained practically unchanged owing to the fact that toll connections require the supervision of an operator even after the automatic equipment has been put into operation. Accordingly, it has been found advisable in the present case to leave the cord circuits at the toll board unchanged and to provide a dial cord, Fig. 2, at each position to associate the calling device with the toll line through auxiliary dial jacks, DJ and DJ Fig. 1.

It will be noted that the line conductor 11 of the toll line TL is normally connected through a jumper on the intermediate distributing frame I. D. F., conductor 28, armature and its resting contact, upper lefthand repeating coil winding, armature and its resting contact, and relay 45 to ground. It will be noted also that conductor 12 of the toll line TL is similarly grounded through a jumper on the I. D. F. conductor 30, armature 51 and its resting contact, lower lefthand repeating coil winding, armature. 54: and its resting contact, armature 56 and its rest-ing contact, and relay 47. It may be pointed out further that conductors 11 and 12 are similarly grounded at the distant end.

The detailed description of the operation of the apparatus shown will now be given. For this purpose it will be assumed first that 05 theoperator in the distant exchange receives a call intended for an automatic line terminating in the exchange in which the equipment shown in Fig. 1, islocated. When the distant operator inserts the plug of her cord .100

circuit into the jack (not shown) on the distant end of the toll line TL, the ground connection is removed from conductor 11 and is replaced by a connection to battery. Conductor 12 however remains connected to ground for the time being. Responsive to the placingofrbattery on conductor 11, relay 45, which is connected to conductor 11 as above pointed out, energizes and closes at armature 58 circuit "for relay 46, at the same time closing the impulse contacts in cluding armature 59 and its working. contact. Relay 46 energizes and at armature 61. places ground onconductor34, .thereby closing a circuit for polarizing winding of the electropolarized relay '43. The design of relay is suclrthat neither winding alone will bring about its energization. Fl'lltllGIlD re, relay 46atarmatures and 62 completes a bridge across-the conductors and 36 leading to the associated lineswitch .as follows: From the negative conductor35, though the working contact and armature 60, upper-righthand repeating coil winding, armature and resting contact, upper winding of the electro-polarized relay 43, lcwer-right-hand repeating coil winding, working contact and armature 62, and the normally closed contacts controlled:- by armature 6.4. Respor 'ive to the closure ofthis bridge, the line switch to which conductors35 and 36 extend operates to .extend the conductors 35 and 36 to a first selector switch in the usual manner.

It will be noted that-the impulse branch through armature 59.0frelay 45 is not closed at this time.

The electro-polarized relay 43 has current flowing through both its windings at this time, but the relayisnot operated on account of the fact that't-he current-is flowing around in opposite directions in the two windings.

The distant operatornow connects her calling device in operative relation in the distant end of the toll line TL and turns the calling device in accordance with the it of the desired number. W'henthe calling device is turned off-normal, the ground connect-ion is removed from-conductor 12 and battery is applied in its place in a manner similar to that tobe subsequently described n connection with a call going inthe oppos te direction. Responsive-to the placing of battery on conductor 12, relay 47, which is conneetedto conductor 12as above pointed out, energizes. At armature 63 relay 47 closes a circuit for relay 48. Relay 48 energi es and closes a locking circuit for itself at armature 66; opens a point in the circuit of relay 42 at armature and at armature 67 places ground on conductor 33, thereby extending a ground connection to conductor 25 to make the toll line test busy at the line jacks L5 and LJ. The ground potential is extended further through and I. D. F. jumper to the cut-off relay 14. Relay 14 energizes and cuts oii the ringing-response relay 15 at armatures l6 and 17, and at armature 13 it places ground on the associated conductor, which is accordingly extended through the 1. D. F. to conductor 22 to operate the mechanical busy signals associated with the jacks LJ and L l. Belay 42.is.not operated at this time owing to the fact that its circuit is open at armature 65 of relay 48.

As a further result of the energization of relay 47 the bridge across conductors 35 and .36 is shifted so that it includes the working contact and armature 59, and armature 64 and working contact instead of the righthand repeating coil windings, the upper winding .of the electro-polarized relay 43, and contacts. 62and back contact 64 ofrelays 46 and 47.

As the distant calling device restores ,to normal, the circuit through which battery is supplied to conductor 11 is brokenanumber of times depending upon the digit for which the calling device is operated. Each time the circuit is broken, relay 45 fallsback andopens the bridge across c0nductors35 and36 at armature Relay 45 also opens the circuit of slow-acting relay 46 at armature 58, but relay 46 remains operated throughout the series of deenergizations of relay 45 due to its slow-acting characteristic.

When the distant calling device again reaches its normal position, the toll line conductor 12 is shifted back to ground again, whereupon relay 47 deenergizes and opens the initial energizing circuit of relay 48 at armature 63. Relay 48, however, remains energized through its locking circuit which includes armature 66. Relay 47 also shifts the bridge across conductors 35 and 36 back to the path originally traced.

WVhen the distant calling device is again turned, relay 47 responds again to condition the circuits outgoing from the repeater R for repeating impulses. In this manner, all the digits of the desired number are transmitted and the connection is extended to the desired line in the usual manner.

W hen the called subscriber responds, the current flow in conductors 35 and 36 is reversed at the back bridge relay of the connector with the result that the electro-po1arized relay 43 responds and at armature 56 disconnects conductor 12 from ground through relay 47 and connects it instead to battery through the resistance 49. This operation results in the extinguishing of the supervisory lamp at the distant cord circuit in a manner similar to that to be subsequently described in connection with a call. in the opposite direction.

Assuming that the called subscriber replaces his receiver i'irst when the conversation is terminated, the electro-polarized relay 43 responds and shifts conductor 12 back to ground again through relay 47 With the result that supervisory lamp on the distant end of the toll line TL is lighted again.

When the distant operator pulls down the connection, battery is removed from conduc tor 11 with the result that relay falls back and opens the circuit of relay 46 at armature 58. Relay 46 falls back and opens the bridge across conductors 35 and 36 at armatures and 62, and removes ground from conductor 34 at armature 61. Relay 48 now falls back and removes ground from conductor 33 whereupon the idle condition is restored at the sleeves of the jacks LJ and LJ, and relay 14 falls back and places relay 15 across the toll line again in series with the condenser 19. Responsive to the opening of the bridge across conductors 35 and 36 at armatures 60 and 62 of relay 46, the automatic switches are released in the usual manner.

Assuming now that the distant operator desires the local operator at the near automatic exchange to complete and supervise the connection, the distant operator plugs in with the result that the lineswitch associated with the repeater R, Fig. 1, operates in the hereinbefore described manner to extend the connection to an idle selector.

The distant operator now throws the usual ringing key associated with her'cord circuit with the result that ringing current is projected out over the toll line TL and operates the ring-up relay 15. WVhen relay 15 operates its armature proper is locked in its operated position mechanically until the armature of cut-off relay 14 operates. At armature 21, relay 15 closes a circuit for the mechanical busy signals associated with the jacks LJ and LJ', and it closes a circuit through the'resting contact and armature for cut-off relay 42 in the repeater R. Relay 42 operates and disconnects the upper winding of relay 43 from around the right-hand talking condenser at armature 52; disconnects conductor 12 from relay 47 at armature 54 and connects it instead to relay 44; and

at armature 55 disconnectsv conductor 11 from relay 45 and connects it to battery through the resistance 59. This latter operation results in the deenergiza-tion of relay 45, with the consequent deenergization of rei lay 46.

As a further resultof the energization of relay 15, a circuit is closed at armature 2O for the answering lamp at the answering jack AJ, which circuit includes a jumper on the I. D. F. and the conductor 24.

Vhen the operator notes the lighted condition of the answering lamp at the answer,

ing lamp AJ, she inserts the plug of an idle cord circuit into the jack AJ, thereby applying ground to the sleeve of the jack. This ground. potential places a busy test on the sleeves of the multiple jacks LJ and LJ. Also a circuit is closed for the cut-off relay 14. Upon the energization of relay 14, the

armature proper of the relay 15 is unlocked and is allowed to assume its normal position. The circuit of the answering lamp is opened at armature 20, and the initial circuit for relay 42 and for the mechanical busy signals is opened at armature 21, but this circuit is maintained closed at armature 18 of relay 14. At armatures 16 and 17 relay 14 removes the ridge including relay 15 and the condenser 19 from across the conductors 11 and 12.

The answering operator now converses with the calling operator and she extends the connection to the desired line in the usual mannor. The former operator has supervision over the called subscriber and when he has hung up his receiver she momentarily throws her ringing key to project generator back over the toll line TL. This operates the usual ring-up supervisory relay in the calling cord circuit to give the calling operator a discon- 35 nect signal.

Assuming now that the operator at position No. 2, Fig. 1, receives a call for a subscriber whose line terminates in the distant exchange reached by way of the toll line TL, the oper- 9o ator inserts a plug into the jack LJ, thereby preparing a circuit for the associated supervisory lamp. The ground potential placed on the sleeve of the jack LJ results in the operation of the cutoff relay 14. At armature 18 relay 14 closes the supervisory circuit with the result that the mechanical busy signals are operated and the multiple circuit is closed for relay 42. At armature 53 relay 42 closes a circuit through armature 57 and its resting contact and contacts on the jack LJ for the associated supervisory lamp. At armatures 54 and 55 relay 42 shifts conductors 11 and 12 from relays 45 and 47 to'battery through resistance 49 and to relay 44. The los placing of battery on conductor 11 through the resistance 49 results in the operation of :the lineswitch on the distant end of: the toll line TL to extend the connection to a first selector.

The calling operator may now operate her ringing key and signal the operator on the distant end of the toll line with results similar to those above pointed out, or she may take further steps to set up the connection automatically independent of the cooperation of the distant operator. Assuming that she decides to take the latter course, the operator inserts the plug P of the dial cord shown in Fig. 2 into the dial jack DJ. This opera- 121;-

tion does not produce any immediate results.

When the operator turns the calling device CD ofi-normal for the first digit in the desired number, a circuit is closed by the offnormal springs of the calling device for relay 101. A multiple circuit is closed through the s eeve of the plug P and through the sleeve or the dial jack DJ for cut-0E relay 41;

Relay 41 energizes and disconnects conductors 28 and 30 from the left-hand repeating 3 relay l1. battery throughthe ring-contact of the plug distant end of conductor 12.

.coilzwindings atarmaturesbO and'51. Asa

ofthe calling device-CDandthrough armature .102 isplaced on'the tip of the:plug P. This circuit replacesthe'battery supply circuit formerly closed through armature 50 of At armature 103 relay 101 places P and throughthe ring contact ofthe associated jack. on conductor 12 with the result that the distant circuits are prepared for operation in. a manner similar to that described hereinbefore. The impulses are transmitted :at the impulse springs of the calling device CD in'theusual manner upon'the return of the railing device to normal. It will be noted that .the circuits of relays 101 and 41 are opened simultaneously at the springs of the calling device CD. Relay 101 however is slow acting and it remains operated for a slight interval after relay 41 has restored so that the holding circuit including resistance 49 is reestablished priorto the opening of the circuit through the impulse springs of the calling device.

After the connection has been set up 'to the called line. the called subscriber responds with the result that battery is placed on the This results in the energization of relay i l through armature and'its working contact. At armature 57 relay 4s: opens the circuit or the supervisory lamp associated with the line jack LJ.

Assuming that the called subscriber replaces his receiver prior to the pulling down of the connection by the calling operator, battery is removed at the distant end from conductor 12 with the result that relay ll falls back and relights the supervisory lamp at armature 57.

When the calling operator gets the disconnect signals from both subscribers, she pulls down the connection.

lVhen the plug is removed from the jack LJ", relay 1% falls back and opens the circuit of relay Relay l2 falls back and shifts the circuit to the p ion shown in the drawing with the result that battery is removed from conductor 11. The connection through the automatic switches in the distant otlice is released in the usual manner responsive to the removal of battery from conductor 11.

Regarding the plug P. this plug may he left in the dial jack DJ indefinitely or it may be removed and used to operate another train of switches in case another call comes in before the last. one cleared out. From this it may be seen that there is only one dial cord needed at a position and that it is used to switch the callingdevice into operative relation with any desired toll line.

Vilhatis claimed is:

1. In :aitelephonesystem, artwo waywtoll lineuautomatic switchingmechanism for extending connections from said toll line at either .end, a sender at one end of said toll line foncontrolling the switches at the other end, said last mentioned switches and said sender being adapted for different systems of control, a repeater at said other end 01" said toll line between the toll line and the associated switches for generating in'ipulses of the type to cause the operation of: the latter switches, a sender at said other end of the toll line for controlling the switches at said one end otthc toll line, and means for connecting said sender direc to the toll aline-onthe toll lineside of saidrepeater.

2. In atelephone systenn'a two way toll line, automatic switching mechan i for extending connections from said toll line at eithenend, a sender at one end of said toll line for'controlling the switches-attire other end, a repeater-at said'other cndot saidtoll :line between the toll line and the associated switches for repeating impulses to the lat ter, a sender at said other end of the toll line for controlling the switches at said one end of the toll line, and means including a manual plug and a spring jack for connecting said sender to said toll line on the toll line side 1 of said repeater.

In a telephone system, a multi-posithin :manual switchboard,a trunk line-extending therefrom and accessible at each position, supervisory lamps individual to said trunk line,'there being a separate lamp at eachposition, contacts individual to said trunk line ateachposition for connecting'up the supervisory lamp .at the calling position only, and means for completing the connection to the lamp upon the termination of the call by the called ,party.

1. In a telephone system, a multi-position manual switchboard, spring jacks at each position, an'outgoing trunk line connected to one of-said spring jacks at each position, means including amanual plug at each position for making connection with the spring jack at the corresponding position, a supervisory lamp individual to said trunk line at each position, and contacts on said jacks whereby the super- '*isory lamp at the calling position only is connected up.

5. In a telephone system, a trunk line, a supervisorysignal at the outgoing end of said trunk line controlled over one conductor only of said .trunk line, a switch control circuit completed over the other conductor only of said trunk line, automatic switchesoperated according to the system of control utilizing both conductors in series, supervisory means for reversing the current flow in the control conductors of said switches, and means responsive 'to the operation of said supervisory means .tor operatingsaid supervisory signal over the first named conductor of said trunk 'line.

control circuit and for completing a dif-- ferent control circuit including the sending contacts of said calling device.

7. In a tele hone svstem. a two-way trunk line, means at one end thereof for seizing said trunk line and for establishin a control circuit thereover, means for associating a calling device with said trunk line at the other end thereof, a cut-off relay associated with said trunk line, means responsive to said calling device being turned oifnormal for closing a different control circuit over said trunk line through the sendin contacts of sai celling device and for operating said cut-off relay to prevent the establishment of the first named control circuit.

8 In a telephone system, a two-way trunk line terminating in an automatic switch at each end, the switch at one end being operable over the two conductors, each conductor in a separate circuit. and the switch at the other end being operable over the two conductors of aline in. series, means at each end for controlling the switch at the other end, and means at one end for translating the control from the other end into'the proper control for the switch. at that end.

9. In a telephone system, a two-way trunk line terminating in a repeater at one end, an. automatic switch terminating; said trunk line at the other end, a jack directly connected to the first mentioned end of the trunk line, means for associating a callin device with said i ack, and means eii'ective when the device is turned off normal to disconnect said trunk line from the repeater and to connect it to the sending contacts of the calling device.

10. In a telephone system, a two-way trunk line, a jack and a repeater directly connected to said trunk line at one end thereof, anautomatic switch at each end of the trunk line, means for associating a calling device with said trunk line by way of said aclr to control the switch at the other end, and means controlled by the calling device to disconnect the repeater from the trunk line.

11'. In a telephone system, a trunk line, a switch control circuit and a switch setting circuit each utilizing one conductor of the trunk line and a separate return, means responsive to the initiation of a call for closing said control circuit, means for producing momentary interruptions in said. control circuit, means for closing said setting circuit during the interruption of said control circuit, automatic switches operated according to the system utilizing both sides of the line in series for setting the switches, and an automatic repeater for translating the. control from the trunk line into the proper control to operate said switches; 12. In a telephone system, an incoming trunk, and an outgoing trunk, means for extending a call, over said incoming trunk, means responsive when a call is extended for closing an impulsing circuit including one conductor of said incoming trunk and a separate return, means for producing a series of momentary interruptions in said impulsing circuit, means for closing a control circuit including another conductor of said incoming trunk and a separate return during the series of interruptions in said impulsing circuit, means responsive to the closure of said impulsing circuit for closing a second impulsing circuit including two conductors of said outgoing trunk in series, and means responsive to the closure of said control circuit for placin said second impulsing circuit under the control of said first impulsing circuit.

13. In a telephone system,a first trunk having two branches at the outgoing end, a repeater terminating one branch, a second trunk outgoing from the repeater, means for operating the repeater over only one conductor of said first trunk to extend a loop control circuit over said second trunk, a relay terminating the other branch of said first trunk, a signal, means for operating said relay over two conductors of said first trunk in series, and means responsive to the operation of said relay for actuating said signal and for disabling said loop control curcuit.

14:. In a telephone system, a trunk having two branches at the outgoing end, an impulse repeater terminating one of said branches, a relay terminating the other of said branches, a calling device associated with the incoming end of said trunk, means for'applying a characteristic current to the incoming end of said trunk, means responsive to the calling device being turned off normal for rendering said repeater efiective for repeating impulses and for disconnecting said relay from the trunk, and means responsive to'the application of said characteristic current to the trunk for operating said relay and for disabling said repeater.

15. In a multi-oflice telephone system, a trunk line comprising two conductors extending from a manual switchboard in one ex change to an automatic switch in another exchange, a calling device at the switchboard, means for associating said calling device with the trunk line, and means responsive to the off-normal movement of said calling device for establishing a current flow over one conductor of the trunk line to render said switch controllable over the other conductor of the trunk line. 7 I 

